text:
What navigation publications are required when flying from KSNA to KAVX?
If I'm flying to Catalina Island (KAVX) from John Wayne Airport (KSNA), which is 30 miles over water, what navigation publications are required to be on board for the route of flight?

The requirements for over land and over water are the same, you don't need any additional publications. Just do thorough planning and a full walkthrough before you go. Keep an eye on your temps and pressures like you ordinarily would, but above all enjoy yourself.

Just keep in mind that there is a right traffic pattern for Rwy 22 and that the sight picture is very different from what you are used to. Be sure to maintain the correct traffic pattern altitude, 2,602 MSL and watch for downdrafts on final. There was a hump in the middle of the runway that obscures the end of the runway so don’t freak out when it looks like you are running out of runway. I haven’t been there since they refinished the runway, so it may have been fixed. My passengers and I always wear life vests when flying there but they aren’t required by any regulation.

Closely related. I'm not sure it's possible to answer this question clearly unless you also tell us the aircraft type (in case 91.503 applies) and if it's a part 91 or 135 operation (all part 135 flights are required to have charts on board).

You'll need the navigation publications appropriate to your flight.  If you're flying under VFR, then you'll need the appropriate sectional chart, and should have airport diagrams.  You'll need to be aware of the airspace and how to communicate and navigate in it.  You should have taxi diagrams.  For VFR flying, I've always made a practice of having the appropriate terminal charts, sectionals, WAC's, and airport publications.  I have also always carried IFR enroute charts, as these provide useful information about communications enroute, as well as airspeed and navigation information.
These days, a subscription to Foreflight usually covers it, and I've flown all over using little else.
If flying IFR, you'll need appropriate IFR publications.
You should have a copy of the airport information, airport facility directory, or equivalent, etc.  If you don't carry and reference the current data, and end up getting busted, you'll have little to fall back on as an excuse.

None of those are required.

Perhaps you can explain why you think appropriate publications are not required.  Do you fly under IFR?  VFR?

@Will - Most posters on this site will take the terms “required” or “legal” to indicate that there is a regulation pertaining to the subject. Unless the poster is flying under FAA FAR Part 91.503, there are no regulations requiring the carrying of current charts in an aircraft while VFR. The pilot only needs to show that they have somehow fulfilled Part 91.103. That does not mean that it is not wise or recommended that they carry current charts. Secondly, the FAA has discontinued the WAC charts.

A pilot is required, as stated, to have data appropriate to the intended flight.

@Will - Part 91.103 states, “Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight.” It does not say that the pilot must have it onboard. You just have to have a way of proving you know the data. I do agree that at least an appropriate paper sectional should be on board every flight. Even if you have some type of EFB. That’s just prudent. It is not required under Part 91 flight under VFR unless you are flying under Subpart F.

@Will - I do agree with you that the pilot in question should carry everything you have mentioned. It is just not required for a light GA piston aircraft.


text:
What are cloud clearance requirements around scuds?
I'm a private pilot (in the U.S.) and I was doing hood instrument training with my instructor under VFR.  I put on the hood and we did an instrument takeoff, and I flew up to 4,500 feet to do some VOR holding pattern practice, all while under the hood.  We were in a Class C airspace.  At 4,500 feet I peeked out from under the hood, and to my astonishment we were surrounded by thin wispy clouds.  I think we even flew through one and couldn't see outside the airplane.  It looked to me that we were obviously in violation of VFR cloud clearance requirements because the clouds were less than 100 feet from the plane and we flew through some of them.  I said this to my instructor, and he insisted that we were still VFR and that I should get back under the hood and
continue the holding procedure.  I insisted again that we were clearly in violation of VFR cloud clearance requirements, and he again insisted that we were fine and we should keep flying.  After three or four times he finally conceded, and we descended and did some practice instrument approaches while clear of clouds.
On the ground after the flight, my instructor said that the clouds were "scuds" or clouds just beginning to form, and that they were see-through.  I'm a little shaken by this because I've worked with this instructor for a year and a half and I haven't seen any reason not to trust him, but I feel a little betrayed by this.  My instructor is probably in his 60s and has been flying and instructing for many years.  If I'm wrong and we were legal to fly through the scuds VFR then I'll admit that, but it seems to go against my education.  Maybe pilots normally fly through scuds with no problem, and if that's common practice for pilots then I guess I'll do that.  But if he let us fly into clouds illegally and then insisted that we keep flying, I'm a little shaken by that because I've worked with him for a long time and he seems to be a good instructor.  I'd like some clarification on this.

Please specify your jurisdiction

This seems familiar-- haven't we had a question like this before?

Does this answer your question? Are VFR pilots required to avoid an isolated cumulus cloud like any other cloud?

Pondlife - no it doesn't.  It sounds like getting close to clouds is technically illegal but pilots do it all the time and it's no big deal.

@SurfandSky Perhaps I misunderstood your question. I thought you were asking about regulations ("violation", "legal", "requirements") but are you really asking if pilots routinely ignore those regulations in practice? Or are you asking if a cloud is still a cloud if you can see through it?

How can you tell how far you are from a cloud?

@MichaelHall -- well, if it's below you and down-sun, one way is to look how big your "glory" is--

how big will it be at 1000’?

From a preponderance of caution, my gauge on clouds is that if you can not see through them to fly by reference to the ground or the natural horizon, it is a cloud. And, a cloud, by any other name (scud, wisp, fog, etc.), is still a cloud. It will obscure visibility.
The question that you have to ask yourself is, “What is the purpose of VFR cloud clearance?” Were you able to see and avoid an aircraft if conflicting traffic was present? Would another aircraft be able to see and avoid you?

Like your instructor, I have flown for forever, and been a CFII for all but 3 of those years.  The test I have always applied, is:
"If you can see through it, it is not a cloud."
In other words the cloud must be opaque as viewed.
However, as in many things, it may not be so simple.  One might reference: How do the FAR's define a cloud??

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


text:
Are three airports or four required for private pilot cross country?
The cross country requirement for the private pilot certificate says that I need to complete a cross country flight of over 150 nm with full stop landings at three points and one leg at least 50 nm.  Does that mean three full stop landing points other than the primary airport, or three including the primary airport?  So if I take off from Airport A, fullstop land at Airport B, fullstop land at Airport C, then return to Airport A, is that good enough?  Or do I also need to visit Airport D for a total of three fullstop landings away from my primary airport?

Part of pilot training is learning how to read the regs you have to follow, which includes learning to read what isn't said. In this case, the reg doesn't say "other than the airport of origin", so by not saying that, they implicitly allow counting said airport as one of the three.

The regulation means you need to land at three separate airports.  This should include landing at your original departure airport at the end of the flight.

§61.109(a)(5)(ii)
One solo cross country flight of 150 nautical miles total distance, with full-stop landings at three points, and one segment of the flight consisting of a straight-line distance of more than 50 nautical miles between the takeoff and landing locations

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Do I understand the rules of logging cross-country time as a Safety Pilot correctly?
Let's say there is a private pilot ("primary pilot") practicing instrument training under the hood and a private pilot who is a Safety Pilot, and the flight involves a landing at an airport more than 50 nm away in VFR conditions.  I want to see if I have this right:

The primary pilot can log instrument time and cross country time, but not PIC time.
The Safety Pilot can log PIC time, but not cross country time or instrument time.
If flying a high-performance and complex airplane, both the primary pilot and Safety Pilot must have a complex and high-performance rating.
The symbiotic benefit of this system is that the primary pilot gets instrument time and the Safety Pilot gets PIC time, both at half price if they split the cost of flying.

According to FAA regulations, do I have this right?

As background, see this question for a general explanation of how safety pilots can log time. Also have a look at the Gebhart (2009) interpretation for the cross-country part (and see this question too).
Note that the two key things to keep in mind in these logging scenarios are:

Acting as PIC and logging PIC time are two different things
You have to be very clear about who is the acting PIC for the flight

With all that in mind (and referring to 14 CFR 61.51):
The primary pilot can log instrument time and cross country time, but not PIC time
The primary pilot can log all three. Whether they're the acting PIC or not, they can still log PIC time as the sole manipulator of the controls (61.51(e)(i)). They can also log instrument time while they're under the hood (61.51(g)) and cross country time.
The Safety Pilot can log PIC time, but not cross country time or instrument time
If the safety pilot is acting as PIC then that's correct. They can log PIC time because they're acting as PIC "of an aircraft for which more than one pilot is required under [...] the regulations under which the flight is conducted" (61.51(e)(iii)). If the safety pilot is not acting as PIC then they can log SIC time.
But either way, the safety pilot may not log cross country time (Gebhart). They also can't log instrument time because they were never operating "the aircraft solely by reference to instruments under actual or simulated instrument flight conditions" (61.51(g)).
If flying a high-performance and complex airplane, both the primary pilot and Safety Pilot must have a complex and high-performance rating
Only the acting PIC requires those endorsements (not ratings), per 61.31(e) and (f). So if only one of the two pilots on board has them, that's the only pilot who can act as PIC.
If only the primary pilot has the endorsements the flight can still go ahead because a safety pilot isn't required to have them. However, the safety pilot couldn't act as PIC and could only log SIC time.
If only the safety pilot has the endorsements the primary pilot can still log PIC time because you don't need the endorsements to log PIC time. But the safety pilot must act as PIC.
The symbiotic benefit of this system is that the primary pilot gets instrument time and the Safety Pilot gets PIC time, both at half price if they split the cost of flying
Essentially, yes. Typical practice is for the pilots to agree that the safety pilot will act as PIC, and they split the costs 50/50 (61.113(c)). That way they can both log PIC time - which is valuable for further ratings - while only paying 50% of the costs. This question has more information on cost-sharing.
And thanks to JScarry for pointing out that if the safety pilot has BasicMed rather than a regular medical, they must act as PIC. See this question for more details.
Whatever you do please be sure that both pilots do know and understand who is acting PIC for the flight. That person has the final responsibility if something goes wrong. Knowing who's acting PIC is important to prevent things like a safety pilot without a complex endorsement agreeing to act as PIC in a complex aircraft, because "I'm just a safety pilot". You might also have insurance or flying club rules on who can act as PIC.

This answer is the most thorough of those given.  I would add though, if there is an incident or accident, the legal (acting) pilot in command will be the one in trouble... not necessarily the one who was flying.  All the FAA has to do, is to look back on past flights to determine who the legal (acting) pilot in command was if there was a disagreement.  Be careful what you log.  I will only log SIC time for my safety pilot time in case there is an issue on the flight.

One thing to note because of a quirk in the Basic Med rules. In the US, if the safety pilot is flying under Basic Med they must be acting as PIC and so would be required to have appropriate endoresments for the aircraft.

@JScarry Good point, thanks! I've added that to my answer.

In your scenario:

Let's say there is a private pilot ("primary pilot") practicing instrument training under the hood and a private pilot who is a Safety Pilot, and the flight involves a landing at an airport more than 50 nm away in VFR conditions. I want to see if I have this right:

The primary pilot logs PIC time as long as they are the sole manipulator of the flight controls, instrument time as long as they are under the hood, and cross country time as long as he flight is made between airports more than 50 nautical miles away from each other.
The safety pilot logs PIC time as long as the primary pilot is under the hood and cross country time as long as the primary pilot is under the during the flight between airports greater than 50 miles apart. No instrument time.
Any pilot logging PIC must be properly certificated and rated. Although, a safety pilot with a private pilot certificate only can log SIC.
The pilots can split the costs or not. It’s up to them at that point. But, if they split the costs, it must be evenly.

#1 is correct. #2 is incorrect. Safety pilot cannot log cross-country time. #3 is partially incorrect. Piltots can agree that the safety pilot is PIC in which case they can log PIC time. If safety pilot is flying under Basic Med they must act as PIC. #4 is mostly correct. They safety pilot can pay no more than the pro rated cost.


text:
Does anyone know more about the 1958 Heinkel-211 project?
Industria Aeronáutica Argentina worked in the 50s in a Jet airliner, Kurt Tank design, the IA-36, 'Cóndor', with simmilarities to 1958 Heinkel-211 project, turbines intake aspirating fuselage boundary layer as some Messerschmitt wartime fighter projects, eg, Me P-1110.
Impossible finding web info about Heinkel airplane, image is from 'Flaps' an Spanish magazine for young aviation enthousiasts. More info?
Blessings +

I have read about it in Ernst Heinkel's biography where it is briefly mentioned. The German Wikipedia also has a brief entry. The project was cancelled when no government funding for the development could be obtained.

From 'Flying' magazine, July 1962.

German Wikipedia has some further details:
https://de-m-wikipedia-org.translate.goog/wiki/Heinkel_He_211?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp
Interesting concept, especially fascinating that you can't see any engines at first glance. But it would have had issues with maintenance (difficult access to the engines) and safety (an uncontained failure of one engine would have been very likely to affect the second one too), so it's maybe better that it was never built...

About an engine failure, they said same about Concorde, Tu-144, XB-70. Never Happened. Servicing this type of engine arrangement has no reasons to be harder than for a Phantom. The ring air intake will suck boundary layer, reducing drag. I see nothing but advantages in this idea. Blessings +

It happened several times with the IL-62 however, which had 4 engines mounted in pairs on either side of the tail section (LOT flights 7 and 5055 - https://en.wikipedia.org/wiki/Ilyushin_Il-62#Incidents_and_accidents). Concorde was a very well maintained prestige project, the Tu-144 had so many problems that it only ever flew one route with one flight per week, and the XB-70 was an experimental bomber of which 2 were built and only flown for 5 years.

Not only Il-62, but VC-10 had same 4 engines arranged as in Caravelle, DC-9. I'd say your concerns proved not realistic. Blessings +


text:
Was there any kind of preventative collision training for dogfights during WWI and WWII?
Watching some old films on YouTube about dogfighting has me curious about this. Definitely seems like most dogfights around this time were extremely close, involving tight formations and turns. Was there any kind of preventative collision training that the pilots went through around this time? Or was the goal just to get them through training ASAP?

I would think that the self-preservation instinct would be a pretty strong "anti-collision" measure.

In WWII, some pilots were sent into action with as little as 20 hours of training, so I'm guessing that collision avoidance wasn't a big topic.

Tight formations were going into the fight and returning to base. In the dogfight itself it was just wingmen trying to cover their leaders from further behind. In the dogfight itself the aircraft are also only just a small part of all the dangerous objects you are trying to avoid.

I would guess "none" is a good answer.

@ManuH I asked this question on another site, and it finally got an answer as well. What do you guys think of this? https://www.quora.com/Was-there-any-kind-of-preventative-collision-training-for-dogfights-that-pilots-learned-before-going-to-war-in-either-WW1-WW2/answer/Jay-Thompson-120?ch=10&share=04950016&srid=erNIm

No, there was no anti-collision training aside from "dodging the fireball" after enemy aircraft shootdown. The training resources and timeline didn't permit much training beyond safe employment of the aircraft gun.


text:
How does density altitude affect Taxi-Out Time?
To keep things brief, for a data exploration project, I calculated density altitude for a couple airports and used flight statistics from https://www.transtats.bts.gov/ONTIME/Departures.aspx.
I was under the assumption that a higher density altitude is bad for performance and would involve things like longer takeoff time which can prolong taxi out time(from gate to runway) since a plane in line would have to wait longer for earlier planes to takeoff. Is this true?
Or is there pretty much such a minuscule difference that density altitude shouldn't matter in the context of taxi out time?

A longer takeoff roll for plane A has probably zero impact on the plane's B hold time because event with a short takeoff roll, plane A would still have to clear the runway before B can takeoff. That said, if the performance is bad enough, plane A may have to do a short field takeoff procedure (basically more flaps and full power before releasing the brakes), which may take a few more seconds to execute. This is pure speculation as I have no data backing this to pretend to an answer though.

It sounds like you have the information necessary to answer your own question (at least a preliminary answer) based on your data. What answer does your data give you? Are you confused because you were expecting prolonged TOT, yet that's not what your data showed?

The time between takeoffs on a given runway is a function of wake turbulence separation from the preceding aircraft, though wake turbulence avoidance times can often be waived by the pilot in command (depending on operating procedures).  Takeoff separation time is calculated based on aircraft type/weight.
An increase in density altitude could determine whether or not the aircraft can do an intersection takeoff, which in some cases could increase taxi time.


text:
What can cause the engine temperature to be high in piston engines?
What can cause the engine temperature to be high in piston engine aircraft?

What engine temperature, exactly? Oil temp? Cylinder head temp? Exhaust gas temp? Coolant temp for a liquid cooled engine?

Low oil quantity, improper cooling, running excessively lean of peak.  Excessive boost from a turbo or supercharger at high altitudes where sufficient cooling is not possible.  Ther are quite a few reasons.

Running lean of peak should actually cause lower CHTs, assuming proper fuel mix (calibrated fuel-injectors, for ex). Martin Pauly has an excellent video on this using his bonanza as an example: https://www.youtube.com/watch?v=h3bATVXMHQg

To a degree, yes.

There could be any number of reasons, and it really depends on the aircraft's systems to determine how it is set up. As always - if you suspect a problem in your aircraft, it's always a safe choice to temporarily ground the aircraft and have an A&P or engine mechanic take a look.
Typically, piston engines (o-320, io-360, etc.) control temperature through two primary means - fuel mix, and oil cooling.
Oil is usually air-cooled as it passes through a radiator, and the cooled oil is used to lubricate the engine. Oil temperature is regulated via the use of a thermal bypass valve to avoid it becoming too cold.
The second mean, by regulating the fuel mixture, is controlled by the pilot. AOPA's 2016 article, "Temperature, Temperature, Temperature" talks at length about how mixture can be used to affect both the Exhaust Gas Temperature (EGT) and Cylinder Head Temperature (CHT):

There are basically three different strategies for keeping CHTs low during cruise:

Baby the engine
Operate very rich
Operate lean-of-peak

Essentially, when you put fuel and air together with a spark, the fuel will oxidize rapidly (burn). This oxidization has an ideal ratio of fuel to air, where both will be used up completely. Excess fuel will lead to incomplete combustion, and excess air will lead to a reduction in available power. This ideal ratio is what we refer to when we say "peak", since it causes the highest temperatures to occur within the engine cylinder.
Operating rich of peak, i.e. with excess fuel, decreases temperatures due to the cooling effect of the uncombusted or incompletely-combusted fuel absorbing excess heat from the combustion reaction. In order for these effects to be visible, however, engines need to be run well rich of peak. This is because adding more fuel does react, even if incompletely, and so the temperature reduction to the cylinder head does not fall off as fast as the EGT might.
Operating lean of peak, i.e. with excess air, decreases temperatures due to a lessening of the combustion happening within the cylinder, along with the excess ambient air causing a cooling effect within the cylinder. Because reducing the amount of fuel available to the engine causes less combustion within the combustion chamber, this causes a decrease in performance.
As the article notes:

In any of these cases, you’re trading power and airspeed for reduced temperatures and increased longevity. For most of us, that’s a reasonable tradeoff to make.

In an engine that's overheating, the forces that cause the engine to cool aren't effectively counteracting those things that cause excess heat. As for what might cause the temperatures to be high in the first place, it could be any number of things. A miscalibrated fuel injector or carburetor,, a problem in the oil circulation that causes poor regulation, a bad seal causing oil to combust, running at too high a power or improper leaning technique, or some other mechanical or electrical issue.


text:
Why are the wingtips of the Fairchild-Republic A-10 bent downward?
Why are the wingtips of the Fairchild-Republic A-10 bent downwards?It is subsonic aircraft .

Good question George, but it think you'll find the answer from the link above.


text:
Why this P-51 limitations placard for diving?
I noticed that this placard has different diving speeds related to altitud. My guess is that those values are a safety speed to prevent going into regions close to Mach 1. I know that the speed of sound is related to temperature. I did some calculation: 260 mph (IAS) is about 525 kts (TAS) @ -56.6ºC which is standard temperature at 40000ft, that's pretty close to the speed of sound. Am I guessing wrong or those limitations have another purpose?

That's correct.  The limitations are to stay below the critical Mach Number, and altitude is used because it's easier for the pilot to monitor and reference to than temperature.  The numbers are based on the standard atmosphere's temperature profile and I imagine there is some fudge factor or safety margin to allow for normal deviations from ISA.
The chart below is from the P-38 training manual which shows more or less the same thing as your placard in graphic form.  The lines become vertical near the top because at about 36000 feet you are in the stratosphere in the mid latitudes and temperature stops decreasing (The Mustang's placard is a bit odd because you would expect the limit speed at 35000 and 40000 ft to be the nearly the same, but there is a 30 mph difference.  Not sure why that is).
The P-38 suffered from a lower critical Mach Number than the P-51 (.68 vs .7) limiting its dive speed at 30000 ft to 290 indicated vs 325 for the Mustang (a major combat limitation until dive recovery brakes were developed - until then, P-38s couldn't chase aircraft in power dives because of the pitch control problems when going transonic).

Placard is in IAS. Chart (and your narrative) are in TAS.

Look at the chart more carefully.  It says 290 IAS next to 440 TAS at 30000 ft in the chart. The Mustang's placard says 325 IAS for 30000 ft.  My narrative quotes the IAS values for both.


text:
How is the type of deicing fluid chosen and how much time is required for application?
From my understanding there are 4 different types of deicing fluids.

How exactly is it determined what type of fluid needs to be used?
How much delay does every type of fluid cause on average?
What is the holdover time for each fluid type?

I am building software for a school project and with the software I want to determine if deicing is needed for a flight.

I'm mainly addressing your "with the software I want to determine if deicing is needed for a flight."
There are three possibilities for whether deicing is needed or not, which are based primarily on actual and expected weather conditions (both at the point of departure, enroute, and possibly at the destination) and the airplane's capabilities:

Deicing is obviously not required
Deicing might be required, but is not obviously required
Deicing is obviously required

No reasonable pilot is going to request deicing in a case where deicing is obviously not required, so that leaves us with the other two. (Remember that deicing costs the airline money, and a pilot who regularly requests deicing for a short local hop in the height of summer is probably going to get talked to by their boss about it.)
If deicing might be required, it's basically at pilot's discretion, likely supported by company standard operating procedures and airplane manufacturer recommendations.
If deicing is obviously required, any pilot who does not request (and wait for) deicing before beginning the takeoff roll is delinquient in their duties, and is putting both the passengers, the crew, and the airframe at risk. Unfortunately, there have been crashes where a decision to not deice in conditions that required deicing were a major contributing factor.
Thus, if deicing is determined to be needed, yet not requested and waited for, then the only safe alternative remaining is to stay on the ground; effectively cancelling the flight.
Consequently, the options are:

Deicing is not needed before takeoff
Deicing is needed, requested and waited for before takeoff
Deicing is needed but not requested, thereby precluding safe execution of the flight

If it is known while the aircraft is still on the ground that a flight cannot be done safely, then the flight should be cancelled.
A flight cancellation can, simplistically, be modeled as an infinite delay.
Therefore, we can conclude that if deicing is needed, then waiting for deicing is required, and whatever this means in terms of additional delay will simply have to be tolerated as a necessity for the ability to safely undertake the flight. It's really not different from inoperative critical flight instruments; if, for example, all attitude indicators or airspeed indicators disagree, you're just going to have to wait to get that fixed, too.
In an ideal world, the choice of whether or not to deice the airplane is entirely unrelated to the time required to deice the airplane.

Trying to answer questions 1 through 3 here. Pilots have two main parameters to think about when deciding what type of fluid to use when de-icing: turnaround time and speed of the aircraft when flying.

Type I has a low viscosity so will usually be used when the aircraft will be leaving soon as it also doesn't protect it for very long, but is useful for slower aircraft has it will also easily flow off the surface.
Type II is more viscous and will, therefore, stay on the aircraft until a higher speed but will also protect it from ice for a longer period of time.
Type III is a compromise between the two, allowing slower aircrafts longer time between de-icing and flight.
Type IV is essentially the same as Type II but with an even longer protection while not in flight.

Source and more information
In terms of holdover differences, as far as I am aware, there isn't any. Each type of fluid is spread on the surfaces from a hose, connected to the reservoir of the de-icing truck, meaning the actual application of the fluid is the same for all types.
From what I know, whenever the pilot calls for de-icing, the choice of type is made when the truck arrives, and the de-icer just selects that types and applies it. Therefore, there is no need to wait for a specific fluid-carrying truck to be available. Some airports even have trucks positioned in specific places on the taxiway and each aircraft taxies through that point to get de-iced before taking off (see below) Again, when the plane arrives at the position, it "orders" the fluid, and it is applied right away.

I don't have a source for this second part, I just used my own experience and observations.


text:
Do jet aircraft have a better glide ratio than propeller aircraft in general? If so, why?
Being fond of aviation, I play with software simulators a lot.
I have noticed that while jets seem to be able to glide for a long distance even at zero throttle, propeller aircraft need to be throttled right up to the runway.
Is this accurate in real planes? If so, why?

There's absolutely no difference as such between the two. If you removed the engines from both, there's no inherent difference.

Note that, naturally, modern airliners (which are all jet) are incredibly better and more sophisticated than old-fashioned historic prop aircraft in every way.  So, totally unrelated to the engines, of course they have incredibly better flight characteristics, including gliding. This has nothing at all to do with the engines. It's exactly the same as that a 2020 model Lexus is staggeringly better in every way (including drag coefficient) than a 1960s muscle car. They have completely different engines (cats versus no cats) but that's irrelevant.

Note that there are PLENTY of examples of propeller aircraft that have incredible gliding characteristics that completely crush the gliding characteristics of the best modern airliners. Two examples:

In the question OP you mention throttle settings. "Gliding" would normally mean with the engines totally OFF. I would guess that nobody here knows or can help with issues relating to what the throttle settings mean in your sim.  (It could well be that in the prop planes the engines are totally off, but, in the jet planes they are still running - who knows?)

Note that if a propellor is just sitting there not turning, yes, it makes a huge amount of drag. (For this reason you can feather many propellors.) BUT then again big jet engines (not running) are huge physical objects, and surely create drag. It would seem to be fairly meaningless to compare the two.  (How would you "compare" them - equivalent power output, or?  The tiny little prop on a small aircraft would surely have far less drag than the huge barrel engines on a jumbo jet.)

This has nothing at all to do with the engines – may I beg to differ? Flight idle of a jet is about 50% of max RPM, so there is still some positive thrust left. An idling prop, on the other hand, is windmilling the engine and has negative thrust, AKA drag. One of the hardest parts in flying the Me-262 was getting that thing to stop, especially for pilots who had only experienced recip engines with props before.

ah, @PeterKämpf , would you please note point "4" and also the general confusion about the question.

@PeterKämpf At the same time, thrust is exponential with N1, so idle thrust is like 3-4% of rated, even though it's running at 50% of its rated RPM.  It's not a linear relationship.

@J Depends on speed. At low speed the idle thrust is positive and at high speed it is negative. And where did I say there would be a linear relationship between RPM and thrust?

@PeterKämpf You didn't - but you made an implicit comparison that suggested a relationship between RPM and thrust where the typical reader would reasonably make certain inferences about what it implied and, typically, that's something like a linear relationship.  Your comment was just unclear and easily misinterpreted to suggest that flight idle produces much more thrust than it really does.  Since the whole discussion circles around that, I felt it was important to clarify.  And yes, at speed, even that thrust is not sufficient to overcome drag.

The excessive bold in this answer is distracting.

"Glide performance" is measured by "Lift-to-drag ratio":

In aerodynamics, the lift-to-drag ratio (or L/D ratio) is the amount of lift generated by a wing or vehicle, divided by the aerodynamic drag it creates by moving through air

When you look for examples you'll see that for the most part larger airliners do indeed have a more favourable L/D ratio

Boieng 747 = 17:1
Airbus A380 = 20:1
Cessna 172 = 11:1

As to why, that is the way they are designed. A good glide ratio is a favourable feature of an aircraft as less drag will imply better efficiency, and airlines are more concerned with efficiency than, for example, a training aircraft which might be more concerned with stability.
More information can be found here: How far can airplanes glide?

Is it just that expensive aircraft are more carefully designed?  E.g. the engine type is irrelevant.

And for a commercial airliner fuel efficiency (and thus L/D) is much much more important than for a sports plane. A better comparison would be between commercial airliners with jets and props.

@AnonymousPhysicist: There are probably many reasons. For instance, retractable wheels add complexity but reduce drag.

@AnonymousPhysicist it's also a factor of production price, ie straight wing is much easier to manufacture than wing sweep (no torsion moment at wing root). But it improves L/D to have swept wings.

It's a bit unfair to compare the glide ratio of a fixed-gear aircraft with that of an airliner. At least the gear-down configuration should be chosen, and then an airliner doesn't look so good any more.

A few reasons: if we're talking glide range from altitude, then jets certainly can glide longer! They fly MUCH higher than most props do, even turboprops! Second, propellers are draggy when they're at idle- you effectively have a big speedbrake on the nose of your plane. This is the reason a lot of planes have featherable props- they can be turned into the wind to minimize drag when the engine fails, increasing your glide range. I hope the answer helped!

Good point on propeller drag: while a jet will still produce quite a bit of thrust at idle, the propeller already creates drag at flight idle.

Why would a jet generate quite a bit of thrust at idle?

@ROIMaison because they move SO MUCH AIR! It's insane how much air they move!

Since a jet is somewhat similar to a propeller surrounded by a fairing -- yes, it's way more complicated, but this captures what I am about to ask -- is there something that makes it idle with so much less drag? Is it that rotation speed at idle is much higher for a jet than a prop?

@RossPresser the amount of air moved is fairly irrelevant, compared with the fact unlike a propeller driven by an IC engine, you can turn the fan of a big high-powered jet engine quite easily with one finger. Unless there is something stopping the rotors from turning, they don't create much drag on the air flow through the engine even if it is shut down.

@RossPresser It's not that jet engines idle with less drag. It's that unlike piston engine that can idle very slow jet engines would stall if it idles any lower. Thus the "massive amount of thrust" that a jet engine generates at idle is merely the minimum amount of thrust it can generate before it shuts down due to starvation of oxygen. You can of course rig a piston engine to also idle at high revs - while most engineers and most common people would not consider such a setting as "idle" for a piston engine, "idle" is just what the lowest throttle setting make the engine run at

@slebetman That is only part of the reason. Turboprops also need relatively high revs to keep running, but the propeller will not create any thrust at flight idle because of the variable pitch propeller. No turbofan has variable fan blades (although Rolls-Royce is working on it).

@MD88Fan, in the context of this question (glide ratio), I think it should relate to engine not operative (i.e. not producing thrust and only drag). Otherwise, I can make an engine with a very thrust at idle and 'glide' until my fuel runs out.

@Bianfable for the glide ratio one does not consider "idle thrust" - that's silly. As engineer you can just pick any number for that and make your plane seemingly "better". - It would mean the glide ratio number is meaningless. Instead for glide ratio "engine off"/unoperatable is considered.

While this is a fabulous answer to the new user's question, it is REALLY confusing to mention the engine running (ie, idling). It should be edited out, as it's just totally confusing.  The question is about gliding.

@paul23 That is true, of course, but I'm not sure if the OP was referring to this case. They say "I play with software simulators a lot" and then "even at 0 throttle", which (to me at least) implies flying at idle, not shutting down the engine.

Mind you, the OP asked about "at 0 throttle" which (perhaps) is not gliding.  What a mess.

I agree w/ @Bianfable 's point, but my overall interpretation is "the whole QA is crap" :/

@Bianfable well it actually makes the premise a bit silly. 0 throttle is a silly mark and a question would be "what is zero throttle actually", and another question is then "glide ratio, huh".

Jet-propelled planes are often aerodynamically 'cleaner' than propeller planes. Hence, drag is smaller and L/D is higher. So they glide much better...

used to be?  so they don't any more?

No... I wrote 'use to be', not 'used to be'... One never knows what the future may bring...

"use to be" is not making a clear point.  Could you express that in another way?  Is it "The intended usage of jet planes requires the most aerodynamic design possible" ?

@Michael actually yes, originally jet (in considering with turbofan) engines were inside the wing, though this gave problems when one engine failed (often causing a cascade of problem), thus regulations made jets kind of obsolete.

To talk about maximizing  glide ratio is the same as talking of maximizing Lift/Drag (derivation can be given, "exercise for the reader"). Since lift is a given when gliding (we don't typically lose weight when engines are inoperative - and we consider a steady symmetric flight). To maximize L/D we minimize the drag.
For a car, or other land based vehicle (car, train etc) this typically means we move as slow as possible.
An aircraft has a different drag profile. Due to the fact that the wing doesn't generate work, bending the airflow downwards also means it has lower horizontal relative velocity (airflow stays same total relative velocity). Thus the lift vector is slightly backwards.
This is the lift-induced-drag. And since at higher velocity we need to bend the air less (more volume of air is moving per unit time), this drag reduces with velocity.
This leads to an image like below:

Now the equation for the drag coefficient is written like:
$$C_D = C_{D_0} + \frac{C_L^2}{\pi AR e}$$
(With $C_L$ being the lift coefficient, $e$ efficiency span factor which counts for winglets etc and $AR$ the aspect ratio of the craft). And $C_{D_0}$ the sum of all parasitic drags.
We are typically quite good at reducing skin-parasite drag. So designing an aircraft for a higher velocity means a better design. Another thing to note is that a higher aspect ratio makes a more efficient gliding craft => hence gliders have long slender wings.
However this would be equal for both props and fan/jet craft. What makes a fundamental difference is another form of parasitic drag: wave drag. Wave drag is massive compared to the other forms of  drag. And it happens where (locally) the relative velocity with air is above mach 1.  (IE on top of the wing, where curvature is maximum you typically have highest velocity). A propeller is moving not only as fast as the aircraft, but is also adding another rotating component, so the tips of a propeller have a higher relative velocity than the rest of the aircraft. Where a fan engine typically has an inlet designed to slow down the incoming airflow, so that the relative speed isn't above mach 1.
For this reason a turbo-prop has to be designed to cruise at lower mach number. This that cruising is less efficient. So picking a propelor as your initial design strategy means you design an aircraft where aerodynamic efficiency is not a main design parameter. Maybe landing/takeof distance is more important, or cheap production/maintenance is a driving parameter.
Since aerodynamics isn't a main parameter it will show in the L/D curve.
If glide performance with paramount I'm sure one could design a very efficient propelor craft, props typically can rotate the blades anyways, so you could at "power off" easily design those to give minimal drag.
It's just not really something to consider.


text:
What precautions are taken to avoid bird strikes?
According to this Wikipedia page on bird strike,

The International Civil Aviation Organization (ICAO) reported 65,139
  bird strikes for 2011-14, and the Federal Aviation Authority counted
  177,269 wildlife strike reports on civil aircraft between 1990 and
  2015, growing 38% in 7 years from 2009 to 2015. Birds accounted for
  97%.

What precautions are taken so that birds are not killed by aircraft?
Is the pilot held responsible or does the pilot pay some penalty in case innocent animals are killed?
Are there any planes which have been designed specifically focusing on bird safety (or have there been any efforts in designing planes focused on bird safety)?
Where can I get reports on the number of bird strikes per year on an international level?

Note: This question does not concern the damages the airline suffers from bird strikes.

Update In Addition To Other Answers
Why jet engines are NEVER protected in the front?!

You should consider splitting this into multiple questions. You are asking four questions at once here.

See this question for worldwide bird strike statistics.

To be "held responsible" implies some sort of malintent/carelessness. I don't think any pilot has much control, nor ill-intention, when a birdstrike occurs. Its not like they fly around looking for birds to hit.

The main answer to the first question from a pilot's perspective is that we dodge them.

Birdstrikes are fatal for the bird and there is nothing in terms of aircraft design that can prevent that. Planes are just too fast. Planes and birds need to be kept separated.

"Does the pilot pays some penalty in case when innocent animal killed?" The pilot is punished by a hefty repair bill at best, and with his ( and possibly his passengers) life in return at worst.

@JimyPP Generally asking multiple questions in one question is okay as long as they are all fairly closely related

While even a trained human eye may not spot birds in time to avoid them.  I'm reasonably certain a radar system specially designed for this would spot birds much further in the flight path.  This would allow the pilot more time for evasive action.  I don't think they are that costly.

@0tyranny0poverty: I'm curious about what information you have about the cost of bird radars and their deployment on the whole fleet of an airline, and what protocols you would implement on air traffic to use them. By the, way, do you swerve on the highway to avoid birds? Do you think it's worth it to crash into another car to avoid a bird?

Related: 1) what precautions are taken so that mosquitos are not killed by the impact with a car's windshield driving faster than 30km/h? 2) Is driver held responsible or does he pay some penalty when innocent insects are killed? 3) Is there any car which has been specifically designed focusing insect safety? 4) Where can I get reports of information of number of insects killed per year on an international level?

@GypsyCosmonaut you might want to consider the simple fact that the real environmental impact of airplanes is that they are very polluting. It is a safe bet that they kill far more species through pollution than the odd bird impact. It seems strange that you'd choose to focus on such a minor source of avian deaths.

In gliders, we actually seek out birds, as discussed in the answer to (this question)[https://aviation.stackexchange.com/questions/2469/how-are-thermals-found].  More than once I've shared a thermal the likes of Turkey Vultures, Hawks and Eagles.

Sorry @usr-local-ΕΨΗΕΛΩΝ , it wasn't funny. 8-|

@terdon 65,139 in 3 years ain't small, imagine if avian industry was source of as many human deaths. And yes, pollution is even bigger problem than that. I totally agree with your point that it leads to more deaths than bird strikes. I see efforts being made in development of electric planes, but we don't often hear efforts being made to reduce these small things which is why discussion on them is also necessary.

To add to @bclarkreston point, I have been told that that some big birds of prey would attack gliders pilot if they were on their territory. So what extra steps do eagles take to avoid glider strike ? Are they being held responsible for the damages ? What penalties do they face ?

Regarding "innocent animals", note that the amount of chickens killed for use as food in airliner passenger meals annually, would exceed the number of flying birds killed by airliners, by something like ten million to one.  While I am sensitive to animal rights friends, there is absolutely zero concern for bird death in airliner bird strike.  (It's perhaps worth noting that wind rofl generators slaughter huge numbers of birds (10,000x more per annum than those that hit planes?  100,000x ?)

@Fattie Thanks for raising the point regarding wind turbines. It's true and I wasn't aware of it.

Right.  I am not even a typical "animal rights person" but wind turbines are basically insane from any reasonable measure, in terms of "completely pointlessly killing masses of birds".  They're basically a political / whatever novelty, which produce no power to speak of, look horrible, and slaughter wildlife en masse. Anyway - off topic.

@Fattie Subjective opinions all apart from 'produce no power to speak of', which is just untrue.

Humans are more important than animals by "most" societal standards. Therefore, bird safety is secondary to human safety (pilots and passengers). However, there are certain areas (in US) that are designated as protected areas for certain types of birds, such as in California where I have seen protected areas for the California Condor which requires pilots to fly at a certain altitude above that area. On VFR Sectional Charts the special conservation areas are depicted as indicated here:

These conservation area restrictions are mostly to avoid disturbing the birds, but I assume it also reduces the risk of a bird strike by requiring the aircraft to fly higher over these areas.
One of the most important precautions is for pilots to remain vigilant and see and avoid, but that is not always possible when a flock of thousands of birds takes off near an airport when airplanes are landing and taking off.
Some airports use various methods (see links provided) to scare flocks of birds away such as using hawks, noise, and other methods.

I don't know of any aircraft that are designed for the safety of birds. I believe this is a very low priority in aircraft design.
Try checking the Audubon Society website, they have a lot of information on risk to birds and statistics on such risks.

Some aircraft are inherently bird-safe: birds can usually dodge aircraft moving at 70 knots or slower, so ultralights and some small aircraft pretty much don't get hit.

"I don't know of any aircraft that are designed for bird safety." Birds hitting the structure of an aircraft are not usually a big deal, except for relatively fragile parts such as the cockpit windows. In any case, birds will only hit the "front-facing" parts of the structure, which excludes most of the fuselage. On the other hand designing and certifying aircraft engines against bird strike is a very big deal, with detailed airworthiness requirements.

@alephzero I’m pretty sure that in that sentence, “designed for bird safety” refers to safety of the birds. Aircraft engines are not designed and certified to ensure safety of the striking birds, but to ensure the safety of the engine.

There is 0.0 concern about bird safety in engine design.  Indeed the bird strike considerations in large engine design is that (obviously) the engine has to survive intact, and that means the animal has to be ideally shredded as finely as possible as quickly as possible.  This is an incredibly difficult engineering challenge, given that some birds are large and the speeds involved are enormous.

In aviation, the question is not what precautions are taken to save birds from being killed by aircraft, the question is what precautions are taken to prevent aircraft being hit by birds.
To prevent bird strikes at airports, several precautions will be taken.
Making birds not feel comfortable in the airport area
This will be achieved by doing following things:

Tall Grass The grass at airports is usually kept tall (> 25cm). This allows mice to hide and many birds, that rely on such food, can't see them.
Removing sources of food In the vicinity of the airport, all occurrences of the rowanberry will be removed. Birds have lost a big food source.

In some cases, fireworks are used to evict birds from the airport area. But this happens very rarely, because the birds can get used to it.
At Frankfurt airport, they have even brought ten foxes to live in the airport. They hope they eat most of the mice, so birds will find even less mice to eat.
Another system in Frankfurt detects big swarms of migratory birds flying over the Main River. Because the Main River crosses the approach on one runway, they always have to know if birds are flying over the river. The system detects swarms and calculates estimated arrival at the runway track. ATC will be automatically warned.
The pilot is also not responsible when innocent animals get killed. It is impossible to avoid a bird. It is usually not seen before impact as well. I talked with a drone pilot from the Austrian army once. He said the crew of an airplane needs around 10-13 seconds to detect an object, to be able to take action. A bird strike can be predicted maybe 1 second before impact. A pilot can do absolutely nothing.
It looks like you like birds very much, me too, but in aviation, human safety is always the first priority.
There are also no aircraft that are designed for bird safety. I can't even imagine how something like that could work. Sorry to say it: aviation has so many other more important things to consider. Saving birds' lives is not important in this industry.

After reading your answer, I saw the Irony here. We a made bird which killed the birds. We care for the bird but not for the birds.

" I talked with a drone pilot from the Austrian army once. He said it takes around 10-13 seconds for a crew of an airplane to detect an object. A bird strike can be predicted maybe 1 second before impact." I dont understand what you mean, does it take 1 second or 13 seconds to detect birds?

A pilot can face stiff fines or community service, though these penalties can be difficult to enforce, as the pilots and FAA rarely honor the results of the proceedings.

Jurors leave the "Massacre on the Hudson" trial after declaring a hung jury.
For instance in the famous "Massacre on the Hudson" trial, matters of poor airgooseship dominated the trial: Whether the inexperienced skein leader was in fact squawking, and whether he was listening to the advice of geese more experienced operating in the New York TRACON. Also, the gaggle had failed to check NOTAGs for the region, though no NOTAGs of concern had been issued.
Ultimately in a second trial, the jury declined to find criminal wrongdoing, and issued a civil sanction that geese should poop on USAir aircraft on the ground when practicable. This seems to have been effective, as such aircraft largely disappeared in 2016.

This answer is as unappreciated as it is well done!  This is precisely the answer this question needs & deserves. Very nicely played indeed!

It is more the other way around: How to save aircraft from being hit by birds and by default; no hit on the aircraft means the bird is happy as well. The danger comes from the bird damaging the aircraft or incapacitating the flight crew possibly causing even more carnage on the ground.
Unless the bird is an endangered species or the pilot deliberately attempted to strike the bird, I am unaware of any "penalties" for a bird strike. If anything, the penalty is going to be harsh in that the pilot or his insurance company for the damage or loss to the aircraft and/or persons. No pilot in his/her right mind would ever deliberately attempt strike a bird in flight.
Yes, the LearJets contain a metal blade from to to bottom in the middle of the windscreen specifically designed as a "bird splitter". This is to reduce the amount of impact against the windscreen (although birds have bypassed the splitter and decapitated pilots). (Reference: http://www.royalair.com/PDFs/Learjet_Product_History.pdf Models 24 and 24A, page 4)
You can contact the National Transportation Safety Board to search for bird strike information as it relates to bird strikes on transportation.

All in all compared to birds striking wind turbines, highway vehicles, etc., the amount of strikes against aircraft are relatively low.

Do you have any reference for the design of the LearJet to specifically have a blade for bird strikes?  That's a pretty amusing fact.

Also, compared to the number of birds killed by wind turbines, aircraft strikes are relatively low.

Are there cases of intentionally hitting birds?

Concerning #3, I don't think the OP had "bird splitter" in mind when they asked about "bird safety design".

@JPhi1618 - Edited to and included reference to LearJet bird splitter in original answer. These devices (blades) were also on the tail of some Gulfstream G450 models to reduce bird damage.

@insanae - Bird Safety yes, but from which point of view? The bird or the pilot? ;)

@corsiKa - I am not aware of any pilot that would intentionally hit a bird. Due to the speeds involved, even a small bird can cause quite a bit of damage depending on the aircraft, speed and construction (i.e; fabric wing or aluminum, wooden spars, etc).

@tnorris the bird, not the pilot.

http://www.tbo.com/news/business/tampa-airport-works-to-limit-danger-caused-by-bird-strikes-20141228/
Gives some examples for our local airport. But essentially:
To protect birds
Don't build airports in habitats that are unique and house endangered birds. Build theme where the birds can go elsewhere.
To Protect the people

dogs
lights
sirens
bangs
guns
bleak barren land
spikes
fencing
lack of food and water

All help keep the birds away.

To answer your question, “What precautions are taken to avoid bird strikes?” Pilots try to avoid birds and areas with high amounts of bird activity as much as possible. We don’t want to strike birds. They damage aircraft and risk human lives. Aviation wether reports, notices to airmen, airfield surface observation radio reports, chart supplements, and other information dissemination resources will note when bird activity is likely at airfields. When a pilot unintentionally hits a bird, there are no civil or criminal penalties in the US as long as the pilot was following acceptable airmanship practices. No aircraft mass produced at this time are designed with the safety of birds in mind. They are designed with the safety of humans in mind. Many organizations like the NTSB will track aviation incidents like animal encounters.
While I can appreciate your opinion and concern for this subject, and applaud your trying to start a dialogue to raise awareness of the issue, it strikes me as misplaced.
I am a pilot who lives next to a nature preserve. I can see first hand the circle of life happen everyday outside of my window. I see a similar circle of life happen at my local Class D airport of similar size. Airplanes contribute a disproportionately small impact on the total number of avian deaths. Nature kills far more birds in the nearby nature preserve than the random aircraft birdstrike.
My local Class D airport is a rather busy airport for its Class and size. Yet, we only see one or two bird strikes a month during some seasons and one a week during other, high bird activity, seasons. Compare this to the multiple birds per day being killed in the local nature preserve of similar size. These deaths are caused by domestic cats, feral cats, bobcats, foxes, lucky coyotes, snakes, snapping turtles, hawks, owls, and other predatory birds and animals. There is even a type of bird who destroys the eggs of other birds. Then, they lays their own eggs in other birds nests for the nest owners to raise. Considering the much larger number of bird deaths being caused by other animals, is there no concern for their death on your part? Especially those killed by domestic cats. These little murderers can kill several birds a day for sport and not for food or survival.
I can not put an exact number on how many birds are killed by other animals. But, a quick internet search will bring up how many birds are killed by man through food production and hunting alone. These numbers are reaching 100 billion birds a year. This makes the 65 thousand in a 3 year period killed in impacts with aircraft pale in comparison. This does not even take into account the birds killed due to the destruction of their habitats by encroaching human settlement.
You are trying to solve a very, very small part of a much larger problem. Your question might as well be what precautions are being taken to avoid innocent birds from being eaten by humans and other animals.

"Considering the much larger number of bird deaths being caused by other animals, is there no concern for their death on your part?" - Bravo!

How Airports keep birds away?
Most airports combine a lot of methods
to keep birds away, such as Standing Lasers, Pyrotechnics, Propane
Cannons, Visual Effects, Natural Predators (i.e. Falconry), Traps and
even adjusting the height of the grass at the airfield.
How does pyrotechnics work at airports to keep birds away?
The key of using pyrotechnics is combining sounds and visual effects to create a
stimulus that attracts birds primary instincts. This can be done with
a variety of pyrotechnics of varying range, colours, and blasts that
can make birds fell that the place is not safe to stay. However, the
correct training of bird controllers is also essential. A true
specialist knows there is not a “silver bullet” in airport bird
control. A complete toolbox and well-trained professionals are needed
for a successful Wildlife Control Program.
What is a birdstrike?
It is a collision between a bird and an aircraft
which is in flight or on a takeoff or landing roll. The term is often
expanded to cover other wildlife strikes.

from: https://airportbirdcontrol.com/airport-bird-control-6-most-asked-questions-and-answers/

You may add robot birds to the list.

Although you've indicated the source of this text, there's no indication on that website that permission is given to copy the content.

David, I am the author of the post...

@CarlosBisio it would be good of you to include this disclaimer every time you post one of your articles. It will save a variety of people having to ask about it, as well as meeting SE's policies about disclosure, and, possibly having your posts deleted as spam (because you don't indicate your link).

Thanks FreeMan, would do it.

Additionally, this doesn't even attempt to answer the question which had nothing to do with airports keeping the birds away.

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text:
Is there a disadvantage to the "fan in fin" design seen for the tailrotor on many Eurocopter helicopters?
A quick google search will show that a lot of Eurocopter models have their tail rotors contained within their tail booms, while a look at Bell or Sikorsky models (and I'm sure others: I'm using Bell and Sikorsky because they're major non-European manufacturers) shows out-of-boom tail rotors. I can see a couple of advantages to the Eurocopter design:

Less danger: the fan blades can be protected from harm and be further removed from people.
Less noise: I don't have empirical evidence for this, but drawing on knowledge of other ducted systems, this design probably produces less noise, at least in the directions perpendicular to airflow.
Pure symmetry: maybe I just like this from an aesthetic perspective, but unlike the unbalanced external tail rotor design, the in-boom design is perfectly balanced.

Is this design less efficient? Is it the space constraints placed on the rotor by the boom?

Related on Wikipedia: Fenestron which a specific section on advantages and Fenestron Tail Rotor

Closely related

The fenestron is a lot heavier than a free tail rotor. This is probably the main disadvantage; helicopters are more sensitive to extra mass than aircraft.
At the time Eurocopter was produced by joining Aerospatiale's and MBB's helicopter divisions in 1992, a follow-on to the successful Bo-105 was under development. That was the Bo-108. Immediately, development was stopped to implement a fenestron into the finished design in order to give all Eurocopter products a common, distinctive feature. This resulted in major structural changes and a heavier helicopter. The result is now known as the EC135.
From this Aerospaceweb article:

The only significant drawback to ducted fans like the Fenestron is
  that the shroud adds weight that offsets at least some of the
  improvements in performance.

As @Koyovis' answer points out, the low position of the lateral thrust vector is also a clear disadvantage. See here for more.

I would also judge a fenestration to be a lot cleaner design in terms of aerodynamics than a conventional tail rotor.

@CarloFelicione: I understood the question to be about the disadvantage, not the benefits of the fenestron.

Major structural changes to a finished design. When designed in from the beginning, the fenestron does not necessarily lead to higher weight than a tail rotor. For one thing, there is a bit of structure removed: the hole where the fan is mounted. Fan-in-fin makes a lot of sense.

@Koyovis: Oh, come on! All that bulging fairing around the tail rotor does add weight. A fin by itself could be much smaller.

Yes true. But a fenestron requires less power, smaller linkage/gearbox etc, which would provide weight offset in a helicopter designed from the ground up to incorporate one.

As you state, the fan-in-fin design has many advantages, the main ones being no blocking of the side thrust by the vertical fin, and shielding of the blade tips from impact with foreign objects.
There are a few design considerations that could be less advantageous:

The fan-in-fin can only be placed at the end of the boom, while a tail rotor can be mounted anywhere on the vertical fin. This can be advantageous in both roll trim (see picture below), in sideways flight and in Dutch roll tendencies. This was found for the AH-64 Apache but probably much less of an issue for a civil helicopter. Source: Raymond Prouty, Helicopter Performance, Stability & Control.
The fan-in-fin shroud must be designed carefully so that flow separation at the inlet lip does not occur.
The fan-in-fin has more blades than a tail rotor, and produces sound that is higher in frequency than that of a tail rotor. The higher frequency sound is easier for humans to detect, but carries not as far as the lower frequency sound. Experiments have been done with sound phase modulation through unevenly spaced blades. Source: J. Gordon Leishman, Principles of Helicopter Aerodynamics.

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text:
How do commercial pilots know turbulence is ahead?
On commercial flights, an announcement will be made if turbulence is expected ahead and if the route will be adjusted such as moving to a higher altitude.
How do pilots know that turbulence is ahead in time to make an announcement and an adjustment? Is it weather equipment in the plane or the ground? Is it because they follow common routes and listen to reports from planes ahead? Are they notified from the ground? Is there some other way they know in time to prepare their passengers?

Aha! That is what I was looking for. It hadn't come up in my search. Thanks!


text:
Why does the F-117 Nighthawk look different than other stealth planes?
The F-117 Nighthawk has flat angled lines where most later designs (B2, F22, F35) have very smooth lines. Why the difference? Are the newer designs 'more stealth'? Do they use a different design to handle better? Is there another reason the distinct angled look is avoided in later designs?
The question, 'Why do many stealth aircraft have a similar shape and design?', is close, but doesn't really address why the F-117 stands out from the rest.
Left: F-117, right: F-22.

I can recommend the book Skunk Works: A Personal Memoir of My Years of Lockheed where Ben Rich explains the history and testing of the Have Blue project and the final F-117.

Initial work on Radar Cross Section (RCS) reduction concentrated on absorbers and had started in Germany late in WW II. The Americans were not interested at the time, but British scientists documented the results and gained early insights in US RCS research when they pooled their results in the 1970s.
Lockheed started work on the systematical reduction of RCS when they discovered the academic papers of Petr Ufimtsev, a Russian mathematician who explained how to calculate the reflection of radio waves from the 1960s on. Their initial success with RCS reduction on the SR-71 was more luck than systematic work. At the same time, similar insights were gained in Germany where a manned prototype of an aircraft (MBB Lampyridae) similar to the Have Blue prototype proceeded up to wind tunnel tests. Then the program came to the attention of US authorities which quickly put an end to it.
In all those cases, the major idea was to restrict the surface to large, flat panels because the edges, not the total area, determine how much energy is radiated back. In that respect, the German design was much cleaner than both the Have Blue and the F-117, but I digress. Those designs can be called first-generation stealth aircraft.
When Northrop joined the RCS work, they found that even curved panels work well - after all, it is edge reduction and alignment which reduces RCS most. Their initial prototype was for a battlefield observation aircraft (in contrast to the Lockheed attack aircraft) which was called Tacit Blue.
When work on stealth prototypes was opened at the end of the Cold War, all engineers could pool their knowledge and combine the work on absorbers, edge reduction and edge alignment. This gave rise to the second generation of stealth designs which look indeed quite different to those of the first generation. What also influenced the designs was more understanding of the tactical value of stealth, so the second generation designs do not optimize RCS above all else but arrive at a compromise which combines low frontal RCS with good agility and multi-role capabilities.
Koyovis is right, but it was not only computer power but also the limitations of early RCS codes which were based - at least in case of Lockheed - on the ideas of Petr Ufimtsev, and he in turn used analytical methods which did not allow to investigate the RCS of curved surfaces. However, the computers at the time were already powerful enough to allow the F-117 to fly at all - in contrast to the MBB design, it is unstable and uncontrollable without artificial stabilization.

While studying aerospace engineering in university, I hypothesized that one could trace everything in our curriculum back to Germany, and apparently that holds true for stealth technology too. Very cool :)

@techSultan: Well, if you ask the Russians, they will tell you that all comes from Russian pioneers. And Ufimtsev really did pioneering work.

My understanding was that the paint on more recent aircraft significantly contributes to RCS reduction beyond what can be achieved with geometric considerations and modifications. Would that contribution help alleviate the need optimizing edge geometry etc.?

@nodapic: No. Absorbing paint was among the first techniques used, so it is not restricted to more recent designs. The absorbers are frequency-specific, so they work only for/against some radar systems. For edge alignment they are no replacement, but they help for example to reduce backscatter in intakes.

The reason I had heard, and seems to be confirmed by this site, is that the computers at the time of design were not powerful enough to compute radar reflection off of curved surfaces.

The photo is from the same site - it sure looks like something only a 70s computer could love. It most definitely makes aerodynamicists weep.

That certainly makes sense if that is the answer. It does look like something from an early video game!

That is also the answer I always heard , however that is not really a proof of it’s validity either.

A parallel development in Germany has a similar design feel to it. This might very well be due to the limitations of computing power at the time https://en.m.wikipedia.org/wiki/MBB_Lampyridae

@rul30 it is indeed the reason. It was mentioned in several books about the ATF competition that led to the F-22 which I read. The available computer power dictated that only flat surface reflections could be calculated in reasonable time, so that's what they ended up with.

It was more the limitations of the algorithms than of computer power. Early algorithms were based on analytical work which used no computers at all.

"It most definitely makes aerodynamicists weep." It probably made flight simulator makers happy, though!

Stealth ships seem to have somewhat similar design: https://www.google.de/search?q=stealth+ships&rlz=1C5CHFA_enDE730DE731&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiuntDG2OHYAhVhD5oKHdN8CegQ_AUICigB&biw=1680&bih=930

Reflection difficult to compute? Hum this is to be confirmed, as I recall early versions of POV ray tracing, that worked not so bad on personal computers.

@mins: remember we are talking about the 1970s and its not ray tracing but diffraction of electromagnetic waves.

@mins- My father played a multi-player, wire-frame graphics flight sim/air combat game (who's name I've long since forgotten) on the mainframe system available at the University of Illinois in the mid-70s (74-75ish). While I'm sure it wasn't as realistic as current flight-sims, ahem, it was pretty darn good. So yeah, computing power back then wasn't as bad as we like to think it was. Of course, every (literal) bit of memory was accounted for as was each CPU instruction...

@mins, raytracing is the wrong tool for dealing with radar waves.  As far as I know, nobody's ever managed to get electromagnetic radiation below about the terahertz frequencies to show particle-like behavior, so you need to use far-more-complicated wavefront simulation techniques.

@Mark particle-like behaviour is irrelevant to whether raytracing is an appropriate tool. For example, it is a perfectly useful technique in seismology, although the energy quanta of earthquake waves (phonons) are way, way to low for to ever exhibit particle-like behaviour. The real reason raytracing isn't sufficient for RCS is that radar wavelengths aren't that much smaller than the size scales of a plane. — Besides, even if it's tricky to show directly in experiments, it's almost completely certain that radar EMR is quantified as photons.

@rul30: Diffraction is a solved problem in ray tracing, and ray tracing itself can be seen as a statisticial approximation of electromagnetic wave simulation. Ray tracing's not just Whitted Style Toy Ray Tracing, but goes much, much further (the terms Monte Carlo experiments, Markov chains, Metropolis sampling, Photometry and Radiometry and more are just a random sample of what is part of modern [i.e. since the 90s] ray tracing)

@phresnel: interesting it did not know that, let's get into that.

@FreeMan: Sounds like PLATO. It was awesome for the time.

@JamesKPolk yes, that was it! Thanks for the reminder.

@rul30: Great question. I am not actually sure if ray tracing is appropriate for modelling stealth devices or for wave modelling in general.

Battlezone! That head-on shot of the F-117 looks like a screen grab from the 1980 Atari console game Battlezone. Here's a link to an image from when the Army adapted the game to train their gunners in the Bradly Fighting Vehicle.


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Why did flight attendants need to be seated early landing at Palm Springs?
I took an Alaska Airlines flight to Palm Springs (PSP) and on landing the flight attendant mentioned that "this is one of the airports where we need to be seated early". Why is that the case for that airport, and what would be some of the other airports where that also happens?

Denver (DEN) is another airport where flight attendants are usually seated early.  Turbulence is common on the descent, because of the terrain.

@NateEldredge: Not just the flight attendants - I remember once flying into Denver (to change planes to another flight to my ultimate destination) and having the "fasten seat belt" sign come on for landing while I was in the lavatory.  I remember being surprised that it came on so early...

I can't say for sure, but here's one plausible reason: Palm Springs is in a valley and surrounded by much higher terrain on three sides, which requires more maneuvering to land than at other airports. You can see on the VFR sectional that the airport elevation is 476ft MSL, but there are mountains over 8000ft within 10 miles of the airport. If you check the instrument approach plates for runway 13R/31L (it's the longer one, so most likely to be used by an airline), you can see that the flight paths are far from straight:

RNAV 31L

RNAV 13R
I can imagine the pilot would brief the cabin crew to be seated well before landing for safety while the aircraft flies the approach. Mountains often produce turbulence and high winds too, which would be another good reason to be seated while maneuvering at a lower altitude over that terrain.

If you've ever been through Palm Springs on the ground, it's definitely abundantly clear why there are so many power generation turbines there. That mountain bottleneck is impressive.

The San Gorgonio Pass Wind Farm, just west of Palm Springs, has more than 4,000 very large windmills with a combined capacity of 615 MW.


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Why are there two red lines on the G-meter in the MiG-29?

Why are there two red lines on the G-meter on the MiG-29 aircraft? One at 7.5G, another one is at 9G. Also on the AOA scale the red line is at only 15 degrees. That is max AOA. It looks very low to me. Or the max G must not have more than the 15AOA? Now it's about the 7.5 G at 15AOA or the 9G at only 15AOA?

Take this with a grain of salt as I don't have a source, but 7.5 might be the G limit in air-to-ground configuration, and 9G  is the limit in clean or air-to-air configuarion

The Mig will be like any other jet limit only 5.5 in air to ground because of the pylons

There is 7.5rated but could go 9G if you want occasionally.

My question is thatAOA limited is much lower than the other types

The first line, you bent it, and the second line, you broke it?

15 degrees is a typical stalling AOA for an airfoil (generally 13 - 16 degrees), so that's not unusual at all.  The G meter, hard so say why there are two marks beyond something like an operational limit and ultimate limit.  You will exceed stalling AOA at max G if are at or below Maneuvering Speed.  If you're going at top speed and you pull, you will hit max G long before AOA gets to 15 deg.

John K you tell me that the Max G is possible below Maneuver Speed (or thecorner speed)with more AOA?

This is a photo from a sim (most likely DCS) not from a real Fulcrum cockpit.  Can you find a closeup of a real MiG-29 AoA instrument?

@JohnK the 7.5 mark on the G meter probably references a limiting load fact, most likely, with external stores on the jet ie heavy bomb load, etc.  it’s just a red warning line to make the pilot aware of this during flight operations.

@GeorgeGeo Maneuvering speed is the speed below which you can't overstress the airframe with pitch control.  You will encounter stalling AOA before that.  For example, when you do a snap roll, you yank back hard to induce an accelerated stall while yawing with rudder and around you go.  You do this with significant margin below maneuvering speed, so the snap is entered (you've exceeded stall AOA) well below G limits.  If you do the same thing above maneuvering speed, you will overstress the airframe.

@CarloFelicione yes I agree with that.  I would bet the small tick mark is a limit with stores and the fat one without.

@GeorgeGeo  If this is your real question "My question is thatAOA limited is much lower than the other types" then you didn't phrase it clearly.  Also if you have knowledge of this "The Mig will be like any other jet limit only 5.5 in air to ground because of the pylons" or this "There is 7.5rated but could go 9G if you want occasionally" then it would seem helpful to include that in the question.

This limits  (for pylons and bombs or fuel tanks)are  pilots to take care of them  to ensure that not being excessive crossing , no need to be marked on gauge because depending on configuration there's to many. There are rolling limits also if aircraft is heavy armed also. So no need to worry about them.

"So no need to worry about them"-- good to know, will remember that the next time I pilot this aircraft.

@George already gave a correct answer, but I'll expand it a bit and show the source.
Indeed, the lower load limit is for trans- and supersonic flight (formally M > 0.85) and the higher limit is for subsonic conditions.
The AoA redline at 15° also relates to M > 0.85. At subsonic speeds, the max AoA is 26°. I can only speculate why it is not shown on the gauge. Normally, the control system will enforce these (AoA) limits automatically.
Here are the load and AoA graphs from the MiG-29 flight manual (or more precisely, its 'Practical aerodynamics' part).

One might notice that the official supersonic load limit is 7 rather than 7.5. I'm not sure why is the gauge showing 7.5.
The curves indicate loads and AoA that are actually achievable at different altitudes (in km). The boundaries are labelled 'structural limits' (on the top) and 'control system limiter settings' (for alpha).
The text explains:

The load applies to the mass 14200 kg, whether with or without missiles. For higher mass, the load limit is reduced by 1 g.
The lower supersonic limit is explained by the lift losses for trim. (MiG-29 is marginally stable at low speed, but (like nearly any aircraft) is highly stable at supersonic speeds, and part of the wing lift must be used to counteract the strong tail downforce).
At M > 0.85, the leading edge droop flaps are stowed, which limits AoA at 15°. At lower speeds, the flaps expand the AoA limit significantly. (There may be further limits; e.g. 13° with a failed SAS (stability augmentation system)).

You are correct about  only 7G's red line, but incorect about you said 7G  being  lower
load limit is for trans- and supersonic flight (formally M > 0.85)" that is for 9G's and" the higher limit is for subsonic conditions".There's a contradiction in terms. Please read first passage of your post

I don't understand. 7G is a lower load than 9G, isn't it? And it applies to M > 0.85. What's wrong with it?

Read this,and you will understand  "Indeed, the lower load limit is for trans- and supersonic flight (formally M > 0.85) and the higher limit is for subsonic conditions."Graphics show  9G until 0.85Mach. Only modify the 7G with the 9 and that correct from the first graph

Yes, and that's what I'm saying. Lower load limit (i.e. 7G) is for supersonic. What is not clear here?

I draw brown lines for you to see that the 9G's is only in subsonic flight  Not Supersonic and 7G is above 0.85 Mach. It is your graphic, not mine

That's precisely what I'm saying! Higher limit (9G) is subsonic, lower (7G) supersonic (and trans-). You don't need to spoil your question, this picture does not belong there.

You are correct about it. Now I see that you haven't been rong. I miss reading your comment.

You could delete the my  comments for your post if you could do it.

The line that is at the 9 G's is limit of maximum amount of G's( 9) until 0.85Mach (that is subsonic speed) and the lower line@7.5 is the limit for supersonic flight.

I can’t comment on the MiG exactly, but most fighter aircraft have maneuvering limitations when heavily loaded with external stores.  If I recall correctly, the F-16 is limited to ~7Gs with a loadout.  A good guess is that the MiG has similar limitations; this would be verified by looking at a MiG-29 flight manual under operational limitations listed therein.

F-16 is 9G( at 15 degrees AOA) capable but only in CAT1( Max AOA  is 25degrees) that is  his AtoAir load. For A to Ground the  stores limit is done by  pylons and weight of all bombs. This is CAT3 limit. Angle of Attack is only 18 degrees max.

The F-16 is limited to 9Gs w/o heavy stores on the pylons; the aircraft, or its sub components, are not designed to withstand more than 6.5-7Gs with a full loadout.  You will have to consult the operating handbook on that aircraft under performance limitations.


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What is the role of discontinuous surfaces on the inside and outside elevons of the F-117?

Why are there discontinuous surfaces on the inside and outside elevons of the stealth F-117? Will that not be highly reflective to the radar?

Yes, you want a knife edge on those surfaces, not a flat panel, for lower radar returns.

Can you please circle what you are talking about?

I believe you are referring to the gaps between the elevons and the other control surfaces?  Those are called cats eye gaps and they’re used to reduce radar returns between the gaps.  Virtually all stealth aircraft use this technology.


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Do the F-18's leading edge flaps deflect symmetrically in rolls?
When the F-18 Hornet does rolls, do the Leading Edge Flaps (LEFs) deflect symmetrically or is the deflection different on the left and right LEFs?

Quoting the F/A-18A,B,C,D Flight Manual A1-F18AC-NFM-000, I-2-42

2.8.2.8 Control Augmentation System (CAS) [...] The lateral control system uses ailerons, differential
  trailing edge flaps, differential leading
  edge flaps, differential stabilator, and rudders to
  achieve the desired roll characteristics. Scheduled
  air data roll rate feedback is used to augment
  inherent airframe roll damping. At high
  airspeeds, aileron travel versus stick movement
  is reduced and the ailerons do not deflect above
  600 knots. Differential stabilator and differential
  trailing edge flap travel is reduced at high speed
  to prevent exceeding structural limits. The leading
  edge flaps deflect differentially up to ± 3°
  when below 30,000 feet and above 0.7 MACH. Differential flaps are not used in the takeoff or land modes nor above 10° AOA in the auto flaps
  up mode. At low airspeeds, aileron and differential
  stabilator travel are reduced with increasing
  AOA to minimize adverse yaw.

In short: Yes the F18 uses differential (asymmetric) deflections on the leading edge flaps and trailing edge flaps but the scheduling depends on angle of attack, airspeed and Mach number.

Hard to emulate that in my sim


text:
Can I get a restricted ATP based on part 61 training?
I graduated from a college with 60 credits that are related to aviation but I got my IR and CPL from out of school which is part 61. Am I still qualified as a candidate who can apply for a 1000hr R-ATP?

It's not really a dupe but this question probably covers the same information. See this answer in particular.

Part 61.160 says no:

(b) A person may apply for an airline transport pilot certificate with
  an airplane category multiengine class rating or an airline transport
  pilot certificate concurrently with an airplane type rating with a
  minimum of 1,000 hours of total time as a pilot if the person:
(1) Holds a Bachelor’s degree with an aviation major from an
  institution of higher education, as defined in §61.1, that has been
  issued a letter of authorization by the Administrator under §61.169;
(2) Completes 60 semester credit hours of aviation and
  aviation-related coursework that has been recognized by the
  Administrator as coursework designed to improve and enhance the
  knowledge and skills of a person seeking a career as a professional
  pilot;
(3) Holds a commercial pilot certificate with an airplane category and
  instrument rating if:
(i) The required ground training was completed as part of an approved
  part 141 curriculum at the institution of higher education; and
(ii) The required flight training was completed as part of an approved
  part 141 curriculum at the institution of higher education or at a
  part 141 pilot school that has a training agreement under §141.26 of
  this chapter with the institution of higher education; and
(4) Presents official transcripts or other documentation acceptable to
  the Administrator from the institution of higher education certifying
  that the graduate has satisfied the requirements in paragraphs (b)(1)
  through (3) of this section.

Unfortunately, I don’t believe you are.  The rule for 1000-hour restricted ATP is that you have to graduate from an approved four-year part 141 university with a commercial license earned at that school.  BoldMethod describes it pretty well:
https://www.boldmethod.com/blog/2013/08/1500-hour-rule-restricted-atp/
There’s also a link towards the bottom of that page that leads to the FAA, which explains the exceptions.


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What are the differences between top and bottom mounted airbrakes?
What are the differences between airbrakes on the top side of jet aircraft (like on the F-15) compared to those on the lower side (like on the A-7), in terms of effectiveness and pitching when they are deployed?

From Wikipedia.

From Reddit.
Would pitch authority be better in one than the other?

Since airbrakes are frequently used during landing, putting them underneath the fuselage could create a ground clearance problem.
Putting brakes on the top only would create a pitch-up tendency when they are deployed. This is countered automatically by the Fly-By-Wire flight controls, so no correction is necessary for the pilot.

I thought that the Korea-era fighters like the Sabre were the closest we got to bottom-mounted airbrakes... then I remembered the A-7... and added it to OP's question because more people need to see the flying ironing board.

The F-4 has airbrakes under the wings and no clearance problem.

The mirage F1 also has airbrakes on th lower part of the fuselage (picture)

The A-6 and EA-6B had them on the wingtips...


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What does this symbol on this Aerodrome Chart mean?
Does anyone know what this symbol on aerodrome charts is?

It almost looks like a printing alignment mark.  Or possible the center point of the aerodrome?  (corresponding to the published lat/long)  I would go to Google earth and see if there is anything physically there in the satellite photo.

It is the Aerodrome Reference Point, ARP.
As per ICAO annex 14 vol 1, chapter 2.2:

2.2 Aerodrome reference point
2.2.1 An aerodrome reference point shall be established for an aerodrome.
2.2.2 The aerodrome reference point shall be located near the initial or planned geometric centre of the aerodrome and
  shall normally remain where first established.
2.2.3 The position of the aerodrome reference point shall be measured and reported to the aeronautical information
  services authority in degrees, minutes and seconds.

The FAA likes to use the term "Airport Reference Point"
Please see the Jeppesen AWM introduction - airport chart legend (pdf). Chart on page two has the symbol with refrence number 17, and on page three this is explained as:

17 — The geographical location of the Airport Reference Point (ARP) is depicted when known.

Brilliant. Thank you so much!

It is a symbol for a referenced location as defined in the “Legend” that explains what each symbol means. That legend, which must accompany a map for it to be useful, is usually found within the first few pages of the directory of airports or at the very end of the book.
I’ve seen that symbol used on some non-government map providers as the Airport Reference Point (ARP) which is stated as the “Location” of the airport using geographical coordinates (N dd mm ss and E ddd mm ss) in the text notes about the airport.
ALWAYS refer to the legend to determine what a symbol means!

The circumscribed cross icon in SACAA charts appears to be a non-descript icon for a radionavigational beacon. The type is not indicated; could be VOR, TACAN or NDB.
They seem to be more common on "sectional" charts than for AFDs; the AFDs I've checked on the SACAA website show FAA/ICAO-style nav beacon types. Compare this Airspace Infringement Hotspot chart for the Cape Town Intl. area with the AFD for the same airport: the beacon's location, but not type, is marked in the wider map, while the more specific symbol for the VOR station is used on the AFD.
This is opposite FAA norms, where the sectional chart (intended to be used from the air to get into and out of airports) shows the specific beacon type with frequency info, while they're usually only shown on the AFD if they're somewhere in the airport that you can taxi to (making them an obstacle you should avoid while moving around the airport), and even then, they're typically displayed as a "black box" indicating a building. The beacon icon on FAA AFDs is usually only for rotating lights.

You are misreading the charts. In both cases, the circle-with-cross is the ARP - even depicted as such in the legend for the color chart. The AFD shows the VOR, but it ALSO shows the ARP (although it's partially obscured by a runway) close by. Jpe61's answer is correct.


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How long does the AFSP(TSA) process take from start to finish for category 3
I paid them the $130 fee a week and a half ago and I'm still waiting for their fingerprinting instructions email. If anyone can share their timeline, that would be helpful.
TIA.